1. Field of the Invention
The present invention relates to an insertion device in which a rotator provided in an insertion section rotates, whereby press force is applied to a second protrusion of an assist tool from a first protrusion of the rotator, and thus the assist tool attached to the insertion section rotates together with the rotor.
2. Description of the Related Art
In International Publication No. 2013/038720, a spiral unit (assist tool) attached to an insertion section of an endoscope (insertion instrument) is disclosed. The spiral unit which is removably attached to the insertion section in a state covering the insertion section from the outer peripheral side, and which includes a spiral fin spirally extended around a longitudinal axis. The insertion section is provided with a rotor, and the rotor is rotatably attached to a base portion of the insertion section around a first revolution axis (longitudinal axis). The rotor is provided with first rollers (first protrusions), and the spiral unit is provided with second rollers (second protrusions). When the rotor rotates around the first revolution axis (longitudinal axis) by the transmission of driving force thereto, press force is applied from each of the first rollers to the corresponding second roller in a rotating direction of the rotor. Due to the application of the press force from each of the first rollers to the corresponding second roller, the driving force is transmitted to the spiral unit, whereby the spiral unit rotates relative to the base portion around a second revolution axis (longitudinal axis) that is substantially coaxial with the first revolution axis of the rotor. The spiral unit rotates around the second revolution axis in a state where the spiral fin is pressed to the inner peripheral side, whereby propulsive force toward the distal side or the proximal side is applied to the insertion section and the spiral unit.